Design and Characterization of Low-Noise Semiconductor Pump Driver in the mHz Frequency Band
In response to the demand for suppressing laser intensity noise in the millihertz frequency band in space gravitational wave detection,based on a low-noise chip and combined with a high stability voltage reference source,this paper designs relevant peripheral circuits to carry out the overall design and development of a semiconductor laser pump driver in a spaceborne laser amplifier.The performance of the pump driver is evaluated from both the time and frequency domains.Experimental results show that when the self-developed pump driver outputs 3.5 A,the current time-domain jitter is≤180 μA within 4 h.In the frequency domain,by converting the current signal into a voltage signal through a sampling resistor,the voltage noise spectral density is less than 1×10-4 V/Hz1/2 at 0.1 mHz and 1×10-5 V/Hz1/2 at 1 mHz.The developed pump driver outputs laser intensity noise with a relative voltage noise spectral density below 1×10-3 Hz-1/2 at(0.1 mHz‒1 Hz)in the frequency range of space gravitational wave detection.This study provides key components and experimental basis for laser intensity noise suppression in space gravitational wave detection.
laser diode drivermillihertz frequency band noise evaluationlaser noise suppressionoptoelectronic feedback control